1. Field of the Invention:
This invention relates to an automatic analytical instrument and, more particularly, to an automatic analytical instrument that dispenses specimens such as blood and urine, and test reagents into storage tubes such as cuvettes and test tubes, allows to react in a reaction unit and optically measures various constituents contained in such specimens at a photometric unit.
2. Description of the Related Art:
In general a blood coagulation test or an immunoassay requires analysis of a plurality of items with respect to specimens. For instance, the blood coagulation test requires measurement of various items ranging from basic items including PT (prothrombin time), APTT (Activated Partial Thromboplastin Time), and Fibrinogen to complex factors including TTO (Thrombo Test), HPT (Hepaplastin test), chromogenic agents, FDP (Fibrinogen and fibrin degradation products) and Ddimer by the use of nephelometery.
Some of the above items include those that have varying reaction conditions such as reaction time and reagent addition time and those that have to use separate photometric units. An analytical instrument that can analyze a number of the above items by the use of random access is desired, but to realize such an instrument, an advanced controlling system is required. Therefore, in recent years, more and more analytical instruments use disposable specimen tubes for reaction and measurement. The reason behind this is that using disposable tubes can dispose of a mechanism for washing the reaction unit and save washing time and that no controls for the above procedure is required.
An advanced automatic analytical instrument using disposable tubes is disclosed in a Japanese Laid-Open Patents Publication No. Hei 8(1996)-9463. This automatic analytical instrument uses cuvettes (storage tubes) as disposable tubes, transfers these cuvettes one by one from a specimen supply unit, via a reagent supply unit, to a reaction measurement unit following a process flow and conducts each test in each cuvette. Since this analytical instrument can conduct individual tests for each specimen, it is perfect for the blood coagulation test that has items requiring various reaction conditions and varying reaction time.
In addition, this analytical instrument can conduct reflect measurements, that is, measure specific items or other measured items again depending on the test results. Since at the time of measurement, first, specimens are distributed by being poured into cuvettes once and distributed by pouring into other cuvettes and then measured, the specimens can be stored in the cuvettes. Accordingly, this automatic analytical instrument enables reflect tests to be conducted without storing specimens of a blood collection tube in a sampler and the like until the test results are obtained and in this regard it is innovative.
However, it is required that in this automatic analytical instrument cuvettes are supplied one by one. In other words, cuvettes are supplied to one by one by a cuvette supplying means (transferring means) disclosed in Japanese Laid-Open Utility Model Publication No. Hei 3(1991)-25157 so that a tube catcher (a turning member) may receive it. It is hard to make the supply speed faster than a certain speed owing to mechanical restrictions. Yet, it is undesirable to furnish this automatic analytical instrument with a plurality of cuvette supplying means from the viewpoint of costs and space.
The objective of this invention is to provide an automatic analytical instrument that can supply simple tubes to fixed positions in a faster and easier way for the purpose of improving the performance of the automatic analytical instrument employing simple tubes such as cuvettes.
This invention provides an automatic analytical instrument comprising a plurality of specimen tubes to store the specimens, a plurality of storage tubes to store a part of the specimens contained in the specimen tubes by dispensing, a first dispensing unit to dispense the specimens contained in the specimen tubes into the storage tubes, a first turning table to hold a plurality of the storage tubes and transfer them by revolution, a plurality of analytical tubes to store a part of the specimens contained in the storage tubes by dispensing, a second dispensing unit to dispense the specimens contained in the storage tubes into the analytical tubes, a second turning table to hold a plurality of the analytical tubes and transfer them by revolution, an analytical unit to analyze the specimens contained in the analytical tubes, a transferring unit to transfer the analytical tubes held in the second turning table to the analytical unit, an delivering unit to deliver the analytical tubes after analysis is completed, a tube supply unit to supply the storage tubes and the analytical tubes to the first turning table and the second turning table into which they fall naturally, and a control unit to control dispensing by the first dispensing unit and the second dispensing unit, revolution by the first turning table and the second turning table, analysis by the analytical unit, transfer by the transfer unit, delivery by the delivering unit and supply by the tube supply unit.
Blood collection tubes, for instance, which can stand on racks, are desirable as specimen tubes. It is desired that the identical tubes be used for storage tubes and analytical tubes and so can be interchangeable, and cuvettes that can be held in a turning table are often used as such. Here, cuvettes mean small-sized tubes storing specimens and reagents for the purpose of observing reactions and conducting analysis and there are no restrictions in respect of shapes. A cylinder with a bottom, a rectangular tube with a bottom, a inverted circular cone, an inverted pyramid, and a combination of the above are desirable and are often used. There are no restrictions with respect to the materials of cuvettes, either, but transparent plastic materials are desirable. Cuvettes can be either washed and reused or thrown away after being used.
The first turning table and the second turning table can respectively hold a plurality of storage tubes and a plurality of analytical tubes in a plurality of holding holes provided on the circumferences and can transfer them by their revolution. The first dispensing unit, the second dispensing unit, the analytical unit, the transferring unit and the delivering unit are provided at prescribed positions in this automatic analytical instrument and composed of known constitution and mechanism.
The tube supply unit supplies storage tubes and analytical tubes to the first turning table and the second turning table, respectively, without using any of variety of means, such as grasping, moving and then letting them go, by making good use of the weight of tubes and dropping them naturally.
The control unit controls at least, dispensing by the two dispensing units, revolution by the two turning tables, analysis by the analytical unit, transfer by the transferring unit, delivery by the delivering unit and supply by the tube supplying unit. This control unit consists of a CPU installed inside the main body of this instrument, various control circuits and various driving motors.
It is desirable that the two turning tables be placed in concentric circles having different diameters. If they are provided as above, installation space and driving motors can be cut down on and miniaturization of the instrument and reduction of cost can be realized.